@antora/assembler/lib/produce-assembly-files.js

A JavaScript library that merges AsciiDoc content from multiple pages in an Antora site into assembly files and delegates to an exporter to convert those files to another format, such as PDF.

'use strict'

const createAsciiDocFile = require('./util/create-asciidoc-file')
const filterComponentVersions = require('./filter-component-versions')
const produceAssemblyFile = require('./produce-assembly-file')
const selectMutableAttributes = require('./select-mutable-attributes')

const IMAGE_MACRO_RX = /^image::?(.+?)\[(.*?)\]$/

function produceAssemblyFiles (loadAsciiDoc, contentCatalog, assemblerConfig, resolveAssemblyModel) {
  const { asciidoc: assemblerAsciiDocConfig, assembly: assemblyConfig } = assemblerConfig
  resolveAssemblyModel ??= (componentVersion) => ({
    doctype: assemblyConfig.doctype,
    insertStartPage: assemblyConfig.insertStartPage,
    rootLevel: assemblyConfig.rootLevel,
    sectionMergeStrategy: assemblyConfig.sectionMergeStrategy,
    navigation: componentVersion.navigation,
    xmlIds: assemblyConfig.xmlIds,
  })
  const assemblerAsciiDocAttributes = Object.assign({}, assemblerAsciiDocConfig.attributes)
  const { revdate, 'source-highlighter': sourceHighlighter } = assemblerAsciiDocAttributes
  delete assemblerAsciiDocAttributes.revdate
  delete assemblerAsciiDocAttributes['source-highlighter']
  const publishableFiles = contentCatalog.getFiles().filter((file) => file.out)
  return filterComponentVersions(contentCatalog.getComponents(), assemblerConfig.componentVersionFilter.names).reduce(
    (accum, componentVersion) => {
      const assemblyModel = resolveAssemblyModel(componentVersion)
      if (!assemblyModel.navigation) return accum
      const { name: componentName, version, title } = componentVersion
      const componentVersionAsciiDocConfig = getAsciiDocConfigWithAsciidoctorReducerExtension(componentVersion)
      const mergedAsciiDocConfig = Object.assign({}, componentVersionAsciiDocConfig, {
        attributes: Object.assign({ revdate }, componentVersionAsciiDocConfig.attributes, assemblerAsciiDocAttributes),
      })
      const mergedAsciiDocAttributes = mergedAsciiDocConfig.attributes
      const auxiliaryImages = new Set()
      Object.entries(mergedAsciiDocAttributes).forEach(([name, val]) => {
        const match = name.endsWith('-image') && val.startsWith('image:') && IMAGE_MACRO_RX.exec(val)
        if (!(match && isResourceRef(match[1]))) return
        // Q should we allow image to be resolved relative to component version?
        const image = contentCatalog.resolveResource(match[1], undefined, 'image', ['image'])
        if (!image?.out) return
        mergedAsciiDocAttributes[name] = `image:${image.out.path}[${match[2]}]`
        auxiliaryImages.add(image)
      })
      const rootEntry = { content: title }
      const { navigation, rootLevel } = assemblyModel
      let startPage =
        'startPage' in componentVersion
          ? componentVersion.startPage
          : contentCatalog.resolvePage('index.adoc', { component: componentName, version })
      if (startPage && startPage.src.component === componentName && startPage.src.version === version) {
        if (assemblyModel.insertStartPage) {
          const navtitle = startPage.asciidoc?.navtitle || rootEntry.content
          Object.assign(rootEntry, { navtitle, url: startPage.pub.url, urlType: 'internal' })
        }
      } else {
        // Q: should we always use a reference page as startPage for computing mutableAttributes?
        startPage = createAsciiDocFile(contentCatalog, {
          src: {
            component: componentVersion.name,
            version: componentVersion.version,
            module: 'ROOT',
            family: 'page',
            relative: '.start-page.adoc',
            origin: (componentVersion.origins || [])[0],
          },
        })
      }
      const mutableAttributes = selectMutableAttributes(loadAsciiDoc, contentCatalog, startPage, mergedAsciiDocConfig)
      delete mutableAttributes.doctype // Q: should this be in selectMutableAttributes?
      prepareOutlines(navigation, rootEntry, rootLevel).reduce((any, outline) => {
        const assemblyFile = produceAssemblyFile(
          loadAsciiDoc,
          contentCatalog,
          componentVersion,
          outline,
          publishableFiles,
          mergedAsciiDocConfig,
          mutableAttributes,
          assemblyModel
        )
        if (!assemblyFile) return any
        if (!any && auxiliaryImages.size) {
          const assembledAssets = assemblyFile.assembler.assembled.assets
          auxiliaryImages.forEach((asset) => assembledAssets.add(asset))
        }
        accum.push(assemblyFile)
        return true
      }, false)
      sourceHighlighter
        ? (mergedAsciiDocAttributes['source-highlighter'] = sourceHighlighter)
        : delete mergedAsciiDocAttributes['source-highlighter']
      return accum
    },
    []
  )
}

function getAsciiDocConfigWithAsciidoctorReducerExtension (componentVersion) {
  const asciidoctorReducerExtension = require('@asciidoctor/reducer') // NOTE: must be required lazily
  const asciidocConfig = componentVersion.asciidoc
  const extensions = [asciidoctorReducerExtension]
  const configuredExtensions = asciidocConfig.extensions || []
  if (!configuredExtensions.length) return Object.assign({}, asciidocConfig, { extensions, sourcemap: true })
  return Object.assign({}, asciidocConfig, {
    extensions: configuredExtensions.reduce((accum, candidate) => {
      if (candidate !== asciidoctorReducerExtension) accum.push(candidate)
      return accum
    }, extensions),
    sourcemap: true,
  })
}

function includedInNav (items, url) {
  return items.find((it) => it.url === url || includedInNav(it.items || [], url))
}

function isResourceRef (target) {
  return ~target.indexOf(':') && !(~target.indexOf('://') || (target.startsWith('data:') && ~target.indexOf(',')))
}

function prepareOutlines (navigation, rootEntry, rootLevel) {
  const singleEntry = navigation.length === 1
  const items = navigation.reduce((accum, it) => {
    if (!it.content || (singleEntry && it.url ? it.url === rootEntry.url : it.content === rootEntry.content)) {
      accum.push(...it.items)
    } else {
      accum.push(it)
    }
    return accum
  }, [])
  if (rootLevel === 0) {
    if (rootEntry.url && includedInNav(items, rootEntry.url)) {
      for (const p of ['url', 'urlType']) delete rootEntry[p]
    }
    return [Object.assign(rootEntry, { index: true, items })]
  }
  if (rootEntry.url && !includedInNav(items, rootEntry.url)) {
    rootEntry.content = singleEntry && rootEntry.url === navigation[0].url ? navigation[0].content : rootEntry.navtitle
    items.unshift(rootEntry)
  }
  return items
}

module.exports = produceAssemblyFiles